Posted
by
Unknown Lamer
on Friday April 06, 2012 @10:25AM
from the we're-all-gonna-die dept.

Layzej writes "The Register reports on a paper published in Science in 1981 projecting global mean temperatures up to the year 2100. 'When the 1981 paper was written, temperatures in the northern hemispheres were declining, and global mean temperatures were below their 1940 levels. Despite those facts, the paper's authors confidently predicted a rise in temperature due to increasing CO2 emissions.' The prediction turns out to be remarkably accurate — even a bit optimistic. The article concludes that the 1981 paper is 'a nice example of a statement based on theory that could be falsified and up to now has withstood the test.'"

I'm not commenting on the climate one way or the other, but when you have dozens of different predictions over the years is it really surprising that a couple of them happened to hit the mark? Don't forget the Global Cooling sentiment which was around just a couple of years before this article came out...

No, because the multiple predictions are not random, the way thrown darts are. This is Science 101. Multiple models are proposed to explain and/or predict an observable phenomenon. The model that makes the the most accurate predictions gains credence over the others.

I'm not a denier, but you're not really countering his point. If 500 scientists make 500 predictions, and one is right but 499 are wrong you can't really point to that one (possibly lucky) guy and say "see, we knew it!".

What if I come up with some new crackpot theory tying the price of tea in china to the average incidence of Herpes amongst 19-22 year olds and then predict the price in 5 years based on that theory. I then get lucky, and the price matches my prediction. Have I totally kicked ass with my new theory of Herpes-driven tea prices?

Like I said, I do believe in man-made GW, but the "other side" can easily find one loon who happened to be right and point to him as proving their point. We need broader theory and broader, more often repeatable tests.

This is James Hansen, head of NASA's Goddard Institute for Space Studies, who has been awarded more honours for science than almost anyone else I can think of... and produced this report when very few scientists were even looking at climatology.

Well, that is a nice example of "proof by anal extraction". Care to actually cite the thousands of not-useful ones? I mean, like, doing science and stuff? Or do you just create your reality by decree ex cathedra?

The problem is the exact same guy has made a lot of predictions. His 1988 prediction, which presumably should be more accurate since he made it with the benefit of more data, was much farther off.

The idea here is, we have a rough idea of the major inputs and outputs, so scientists have to guess at the coefficients and constants. There are a number of them, positive and negative, so you can actually be wrong on every single one of them and still get the right answer. In this case, it appears he was off by 30%, which isn't a very good indication of predictive power. (Yes I know his prediction was under, but the goal here is accuracy, not who can predict the best disaster).

When I get home from work I'll have a chance to read the paper in more depth, to get a better idea of how random his guesses were. It is definitely true that in 1988 he thought his prediction was better.

It's worth noting that Hansen predictions got worse [realclimate.org] when he testified before a 1988 committee of Congress in the usual staged congressional hearing. Sure, these predictions aren't random, but the way they aren't random often is unscientific and biased.

That in itself says nothing about whether it is actually correct in itself just whether it makes good predictions. A simpler model that makes exactly the same predictions would be prefered - that's what Occam's razor actually says after all. If the models make different predictions we don't need the razor we just see which one (if any) matches reality.

If you can predict the climate, publish your predictions for each and every weather station so we can compare predicted values to actual values. (Oh, and yes, I do know the difference between weather and climate.) But no, we get some hazy predictions for something in 100 years, yet nothing for next year.

It's funny. You claim that you know the difference between weather and climate, and yet you repeatedly mix up the concepts the rest of the time. If you know the difference, why do you want to be given a prediction for a specific location? If you know the difference, why do you want to be given a prediction for the coming year?

The bizarre thing is that if you look at the graph you can see what they thought it would be next year, and indeed all years to the end of the graph. As it gets further into the future then the error range gets bigger because they can't know what the human response to this problem would be.

Moronic arguments about weather vs. climate are not science.

And moronic arguments that get weather vs climate wrong are also not science. This doesn't change merely because you keep mistakenly claiming that you do know the difference.

I don't understand your comment. The last "mini ice age" was in the early middle ages, far before climatology or anything approximating it existed. Could you characterize what you mean there being a frenzy, and identify some of the related publications/records associated with it?

It's cherry-picked info. (I'm not saying Climate Change is not happening, just saying this is not science). I'm not sure what part of this data is falsifiable. It doesn't have any kind of error analysis and some of the assumptions are known to be false or be different than expected. You can't simply say, "It will get warmer", be off by as much as 30% and get credit for good science. This is the kind of thing that drives me nuts. Climate change *could* be a serious thing but it gets washed up with politi

The first thing I thought when I read this yesterday was that this is how they "fit after the fact" Nostradamus predictions of the latest great tragedy. I also remember a lot of "12 inch sea level rise but the turn of the century" from that time period that didn't come true. So, yeah... The credibility thing is a bit strained.

Honestly, I think you should have kept that to yourself, because on second thought it doesn't make much sense. Nostradamus' "predictions" are incredibly ambiguous, which is why they can be made fit observations after the fact. Quantities such as degrees Celcius/Fahrenheit are not; the observations either fit within the specified level of precision or not.

If one looked at a whole bunch of models from the 80s, and saw how they did on average, then you'd be looking at the typical assumptions that models made in the 80s, and how well those assumptions panned out. It is reverse cherry-picking and shifting the burden to instantly assume that the study was exceptional compared to the predictions of peers at the time. Basically you are saying that, to convince you, someone has to find all the models done in the 80s, and score them all. (I assume that "skeptics" wou

You mean the way Einstein predicted things that "fit after the fact"? Just last year we found at least one more of his predictions was true. He's just like Nostradamus, right?

A model gets proposed, then tested. The ones that are closest to reality are proven correct, the ones that don't are proven incorrect. You are saying that this person's credibility is strained because a lot of other people were wrong? If that is how we measure credibility, then how is anyone supposed to be credible?

You are saying that this person's credibility is strained because a lot of other people were wrong?

Yes. Exactly this. The problem is that all of the summaries, and archives and research are now so tainted by political agenda on both sides, that all of it is questionable. How can the non-professional know what is solid an what is tainted now? Not a good thing... Not a good thing at all. The truth should not be this hard to find!

It's hard to find for the non-professional because it's hard for the professional. We don't have enough data.

If we had multiple earths, and could run double-blind experiments, then there would be no problem. As it is, we only have 60 years of good, solid temperature data, we don't know the warming effect of the atmosphere to within 10 degrees, and the climate is a chaotic system.

So we try to use short cuts, like simulating different atmospheric compositions in bottles, or extrapolating from the data we

I see no evidence that you even read this paper. All you are doing it spouting the standard denialist memes: it's cherry picked; it's not science; it's not falsifiable, etc. You say there is no error analysis, but does that mean that they gave a single temperature prediction? No, even just looking at the graph in the article you can see there is quite a wide range to their prediction with different areas based on what the human response to this problem was.

You say some of the assumptions are false? Which ones? Why did you not include even a single example of how they got it wrong? And here is the my biggest problem:

You can't simply say, "It will get warmer", be off by as much as 30% and get credit for good science.

I did a search in the article for the text "It will get warmer" and could not find a match. It seems that the scientists behind the paper agreed with you, and so they didn't just make a single proclaimation without showing any supporting evidence.

Climate change *could* be a serious thing but it gets washed up with politically driven junk from activists. They are doing more harm than good.

Surely it is the skeptics that are doing the most harm. You know the ones. They have claimed over the past decade that global warming is false because it is actually getting cooler (although they have had to change this to claim that the temperature has remained steady once it became obvious that it was not getting cooler). They are the ones who make claims about climate changes without providing any supporting evidence, but will also deride scientists (who do actually show their working and their data) as doing the same.

Only if they consistently make accurate predictions, and not just hit the Loto once.

Unfortunately, for this particular research area, we only have one planet to experiment on. So they can't exactly reset the planet back to 1981, change the amount of CO2 in the atmosphere, and re-run the experiment to see what the difference is.

Besides, they didn't just randomly draw a curve on a piece of paper, they designed a mathematical model, fed data into it, and made predictions based on that.

There's a difference between a scientific theory that ends up correctly modeling reality for a long period of time and me just making wild guesses. However, a lot of people will conflate the two, saying that all those scientists were doing was making wild guesses that happened to pan out. This is the same kind of thing that creationists say, when they point out that evolution is "just a theory". It also allows them to create their own competing "theory", consisting of a bunch of mythological stories.

Science is not just a bunch of old guys with wild hair who sit around, pulling shit out of their ass, and saying, "Hey, this sounds good. Let's go with this wild guess. The public will eat it up, and we'll get more grant money!"

Science is not just a bunch of old guys with wild hair who sit around, pulling shit out of their ass, and saying, "Hey, this sounds good. Let's go with this wild guess. The public will eat it up, and we'll get more grant money!"

Actually, it does include people like that too... And unfortunately, those guys are most likely to get the press. For the record, "Peer Reviewed" is not USA Today.

Science is not just a bunch of old guys with wild hair who sit around, pulling shit out of their ass, and saying, "Hey, this sounds good. Let's go with this wild guess. The public will eat it up, and we'll get more grant money!"

You're correct. What you describe is the mainstream tenured academic world, not capital-s Science. There are always some scientists out there working in the corner somewhere, unnoticed.

I think with some common sense and a little science, it's not hard to figure out whats going on here. Same thing was said about Cigarettes and Cancer, how much more proof do you need that there's repercussions for doing bad things. Just look around you, look at what we are doing.

The big difference between CO2/Global warming and cigarettes/cancer is that for cigarettes cancer, we have all the people who don't smoke, and are not exposed to copious amounts of smoke as a control. For CO2/global warming, no control exists. Temperatures have always fluctuated, and so it is difficult to discern whether we have a trend or not, therefore it is harder to be more certain as to the effect of CO2 on the climate.

And besides, I have not seen too much evidence that CO2 does bad things. My own not

And besides, I have not seen too much evidence that CO2 does bad things.

Well, it depends on your notion of causality. Increased CO2 concentration, by itself, is a relatively minor thing. But there are many effects of increased CO2 concentration that are, in fact, bad. The two major ones that I can see are increased global temperatures leading to climate change and ocean acidification. The severity and validity of the former is still hotly debated, the latter hardly gets any attention at all.

And it's not just CO2 causing global warming. Humans have cut down 1/3 of the world's forest and built millions of roads. Plus all the live stock creates lots of methane (another global warming gas). It's the combination of many things that we do, causing climate change.

That is, indeed, an uninformed hypothesis. Experimental test, however, have been made.

In the tests that I'm familiar with high temperatures and increased CO2 did, indeed, produce rapid plant growth. They also yielded plants that had weak stems and were deficient in protein. This is not a net gain. And if you raised the temperature a bit more the plants didn't even grow faster. Also, this is presuming that extra water was available. I'm sure there have been other tests with slightly different plants or

Sure you are. You're argument in a nutshell, goes like this:1. Premise: There were hundreds of predictions about what would happen to the climate over a 30 year period.2. Premise: One prediction was demonstrably right.3. Inference: because 99.9% of the predictions were wrong, the one that was right must be due to pure chance.4. Final conclusion: I can safely ignore any other prediction about climate from anybody, because the only way it can be right is by pure chance.

Well, that's not how science works. The logic of science works more like this:1. Premise: There were hundreds of predictions about what would happen to the climate over a 30 year period, each using different models and ideas to arrive at that prediction.2. Premise: One prediction was demonstrably closer to right than the others.3. Inference: The models and ideas that produced the correct prediction are closer to the truth than those that didn't correctly predict a result.4. Final conclusion: When making the next prediction, start from using those models and ideas and you'll get pretty close to the right answer.

Here's a similar problem from physics:Model A: Acceleration due to Earth's gravity near the ground in a vacuum is ~10 m/s^2, so the ball should fall 100 meters in 4 seconds.Model B: Acceleration due to Earth's gravity near the ground in a vacuum is ~5 m/s^2, so the ball should fall 100 meters in ~5.8 seconds.Time for a ball to fall 100 is slightly over 4 seconds. Ergo, 10 m/s^2 is less wrong than 5 m/s^2.

In the words of Isaac Asimov, Model A is wrong, Model B is wrong, but if you think that Model A is as wrong as Model B, then your view is wronger than both of them put together.

A model does not have to produce the closest prediction for it to be the most correct model. Getting the closest prediction can be completely down to chance.

For example, how much CO2 did he predict we would have put up there. How much rainforest depletion did he allow for. How much did he allow for other greenhouse gases. It could turn out that he predicted much higher temperatures based on a much smaller amount of CO2 emitted, which would make his model wrong

Model A: Acceleration due to Earth's gravity near the ground in a vacuum is ~10 m/s^2, so the ball should fall 100 meters in 4 seconds.
Model B: Acceleration due to Earth's gravity near the ground in a vacuum is ~5 m/s^2, so the ball should fall 100 meters in ~5.8 seconds.
Time for a ball to fall 100 is slightly over 4 seconds. Ergo, 10 m/s^2 is less wrong than 5 m/s^2.

In the words of Isaac Asimov, Model A is wrong, Model B is wrong, but if you think that Model A is as wrong as Model B, then your view is wronger than both of them put together.

This example is clueless: the OP wasn't questioning the identificated parameters of the model, but the model: in your example both models are the same!

To show you how wrong your example is:
Model A: acceleration due to Earth's gravity near the ground in a vacuum is 9 m/s^2, so according to A a 0.5 kilos ball should fall 1000 meters in ~14.9 seconds.
Model B: acceleration due to Earth's gravity near the ground in a vacuum is (4 + weight/0.086) m/s^2, so according to B a 0.5 kilos ball should fall 1000 mete

In my example, both models had acceleration due to gravity as a constant, determined to be that way from previous experiment or theory, and so the question was what that constant actually was.

And of course, Model B goes to pot as soon as you change the parameters of the test, dropping the ball 100 meters instead of 1000 meters, dropping a ball weighing something other than 0.5 kilos, etc. In the case of climate science, the model not only has to predict where things are now, it obviously has to predict many data points in between 1981 and now.

Alternately, and this seems to be the standard demanded by those who disagree that climate change is real, we could build a second planet Earth, place it in a clone of our solar system, and then try different levels of carbon emissions to see what happens. The obvious objection here is that such an experiment could not be carried out.

Here's a similar problem from physics:
Model A: Acceleration due to Earth's gravity near the ground in a vacuum is ~10 m/s^2, so the ball should fall 100 meters in 4 seconds.
Model B: Acceleration due to Earth's gravity near the ground in a vacuum is ~5 m/s^2, so the ball should fall 100 meters in ~5.8 seconds.
Time for a ball to fall 100 is slightly over 4 seconds. Ergo, 10 m/s^2 is less wrong than 5 m/s^2.

The Global Cooling was a prediction for the year 5000, not for 2100. It might confuse you, but actually both Global Warming and Global Cooling could be correct. We have proof that in 1981, there were sufficiently exact climate models for the last 30 years, and we have good arguments, that the Global Cooling is a valid prediction too.

I can see you did not want the karma hit from bringing rational debate into a climate article on slashdot...:) Allow me to compliment your insightful post before you are modded into -1 Troll oblivion along with me.

I actually know people at NASA. I know some back story on how that "consensus" came about. Most of the scientists only agree with about 60% of it. Which 60% varies a LOT, and the discussions were very spirited. They all agree there is global warming, and they all agree we are contributing. How much, and how, and what we can do to effectively change that is causing a lot of "discussion." But that part never makes the report.

"Who do you think is funding the side that's supported by 90% of climate scientists worldwide?"

The side that seeks to exercise power over us.

And yes, the 'other' side does also. They just seem to have different intentions for that power.

Under Crony Capitalism, none of this matters. We hear the policy debates, and meanwhile everyone in power is busy getting rich and ingratiating themselves to their conspirators, who are sucking us dry.

I was just going to point out to GP that we invented all the mobile phones and mp3 players and other cool stuff he wastes his time playing with, so we have some small claim to knowing things about science.

I am very far from being a specialist in this topic. The The Register article seems to imply that global warming must be true, given that there was ONE paper in 80s already anticipating it. That is not necessarily true. The prediction can be result of pure chance in a possibly erratic research study (I have no clue if that is the case or not). One could perhaps make an stronger statement in that direction if MANY papers anticipated global warming (possibly using different models).

Once again, how this relates to climatology has been explained over and over to you. You still keep on posting your same old bullshit. Now, I do not think that you are actually that stupid, you are able to form semi-coherent sentences and all that, so that leaves us with one conclusion only - you are an intellectually bankrupt dishonest liar. And you know it. And, to preempt your usual reply - no, this is not an ad hominem. This is an insult.

And if you take pretty much the same data, over time, and show when the sunspot activity grew & shrank,
I bet you would show that the temperature rise pretty much is spot on with the rise in geomagnetic activity
from the sun, which is what heats & cools this rock we call a planet!
But, considering the stupidity of "modern" man, the only thing they will read out of this is that temperatures
are rising!
Back when I was in high school in the 70's, they were talking about a mini ice age....but unless yo

So, in yesterday's story about predicting the collapse of civilization, multiple posters snarked about how convenient it is to make predictions about what will happen 30 years from now, 'cause no one will remember you made those predictions--so you'll never be called to account for your oh-so-incorrect doomsday predictions.

I now calmly await for yesterday's posters to issue "I can see now that I was wrong" statements.

I'd actually worry about yesterday's prediction, though. We have an enormous problem with our worldwide food supplies and too many people to feed. Too much trash and negative impacts on the environment as well. Combine that with the fact that middle east oil will be largely gone by then, and the situation is ripe for another world war at the least.

So about 8 years ago I moved from Minnesota to Northern Virginia for work. And one of the aspects of culture shock was that I was now living with, befriending and enjoying my time with folks from all over the country who had moved to the DC area for work. Many friends from Texas and Pennsylvania specifically. I even roomed with several of them and one thing really bothered me: they did not recycle. So I kept doing my own recycling and trying to help them out to no avail. This was quite different from Minnesota where it was stressed when we were young that it was important. You might call it common sense or indoctrination or nanny state or whatever your political views tell you to but that's just the way it was largely. And the reason was that the Earth is a precious resource.

So, being an avid Slashdotter, I was fairly in tune with the Global Warming debate and would often talk to my new friends about it. Every single one of them either didn't want to hear it or thought I was an idiot. They seemed to only listen when I would bring up news items lending credibility to the absence of climate change. Then they asserted there was climate change but it is natural and so on and so forth. To this day, my friend from Texas does not recycle in his home. His Korean wife has asked me not to discuss global warming around her and continually asserts it was proven wrong years ago. My friend from Texas, being quite a bit smarter now likes to talk about what we can do about it without him having to alter his lifestyle at all. The reason for it is unimportant to him, now he just accepts that it's happening for some reason and how can we put something in space that can block the sun partially while maintaining a synchronous orbit around the sun between it and Earth. It's not that that is a simpler solution than reducing your personal carbon footprint but instead it's one that doesn't require government intervention (which he views as the ultimate evil) and doesn't require him to change.

So what do you do when you read news about this, do you whip out your biggest "I told you so" font and e-mail it out to your friends until they get tired of it? I mean, I can't even politely offer to collect the cans and bottles from one of my friend's parties and take them to the local recycling center. He's almost proud of his freedom to be able to send it to the dump. So I have two options. One is silence and apathy and the other is not having any friends in this area. Silence and apathy it is.

(We're in the same area, it seems. I moved to NoVA about 2 years ago for work.)

Have you seen the Bullshit [youtube.com] episode on recycling? It might interest you. It seems that only aluminum and possibly steel are worth recycling from a net-energy/resources savings standpoint.

Plastic I recycle just to avoid the whole plastic forest [thescope.ca] issue. And, of course, all the damn bags that end up in the rivers around DC. My wife takes all the paper, shreds it and uses it in her compost pile.

But if you were to address the central conceit of CO2 driving warming, would you accept it as falsified if say, we saw in the historical record of some ice core rising CO2 for 50 years, but falling temperatures?

Of course not, but you would probably be naive enough to believe this. You'd need to know more about the natural variability and the radiative forcings acting during that period. Which is why I keep telling you that climate science is based on examining the physical origins of temperature responses and not naive correlations.

Which, you've admitted, is completely unknown information. And yet, you blithely believe you can discern between natural climate change, and unnatural climate change:)

Geeze, how dumb are you. It's completely unknown information in your hypothetical example which was specifically contrived to only present information about CO2 and temperature. In reality, we know something about natural variability and radiative forcings.

I wish coversation around this topic would shift from debate about whether or not the climate is changing and may in fact change dramatically over the course of several decades, and whether or not humans activities have an impact on the climate to a productive conversation about how to best react to changing climate and use it productively. It is obvious to me that where I live (Minnesota), the mean temperatures are rising and the growing seasons are getting longer. Shit, I had my vegetable seeds sprouting and even had them outdoors some days, early in March, in Minnesota! I am also growing a dwarf bananna tree that has made it through two winters here. I guess my point is, I think it would be great if people would quit arguing about empirical facts (such as there is more CO2 in the atmosphere than ever before during modern human civilization); and start wondering about how to react to the changes that might be brought about in this altered environment.

Seriously, things don't go in a straight line forever. Further, they were quite totally wrong, in that their predictions were too low. I don't know what the big deal is, other than AGW people glorying in their own selection bias.

That's great work, you've shown that complex, data-based mathematical modelling by NASA scientists is just like someone drawing a line between points and cheering when it later turns out to match some data. And you did so with a cartoon!

I'm sure NASA will be pleased to learn that they can forget all that tiresome building of models and instead base all future rocketry on connecting-the-dots. I thank you, good sir.

I'd wager you would fall into one of those believe-anything groups, tmosley. Every comment you make bets on a world of endless oil and no climate change. Let me make some verifiable predictions about you based on your commentary:

1) You drive a big, gass-guzzling pickup or SUV2) You live in a predominantly rural state like Texas or Montana -- definitely not East Coast or West Coast3) You believe Obama is a socalist and suspect he's secretly a muslim4) You generally vote Republican or for whoever's right of

From the Hansen study:"Political and economic forces affecting energy use and fuel choice make it unlikely that the CO2 issue will have a major impact on energy policies until convincing observations of the global warming are in hand."

"a nice example of a statement based on theory that could be falsified and up to now has withstood the test."

Just wait till we finally reach a double of atmospheric CO2 values, at which point we'll get to see if the predictions Svante Arrhenius made in the late 19th / early 20th century pan out.

If the quantity of carbonic acid in the air should sink to one-half its present percentage, the temperature would fall by about 4 degrees; a diminution to one-quarter would reduce the temperature by 8 degrees. On the other hand, any doubling of the percentage of carbon dioxide in the air would raise the temperature of the earth's surface by 4 degrees; and if the carbon dioxide were increased fourfold, the temperature would rise by 8 degrees.Although the sea, by absorbing carbonic acid, acts as a regulator of huge capacity, which takes up about five-sixths of the produced carbonic acid, we yet recognize that the slight percentage of carbonic acid in the atmosphere may by the advances of industry be changed to a noticeable degree in the course of a few centuries.

This paper tries to predict temperature changes based on multiple scenarios of CO2 ppm emissions.

There are 2 fundamental problems, however. 1) There were no uncertainty ranges given. We can't say that a 30% deviation from one of the scenarios is accurate or inaccurate without these ranges. 2) The actual CO2 ppm emissions do not fall within the bounds of any of the proposed scenarios.

All we can say, definitively, is that events transpired outside the bounds of any of the scenarios and the results

I would also be interested in knowing about other predictions, in particular predictions with specific numbers backed by plausible theoretical models, published in a respectable venue like Science or Nature (or some more specialized but still solidly peer-reviewed journal).

If indeed it turns out that there were a few hundred such models/predictions, and one turned out to be close to right, that would not be super impressive. But I'm not able to find those hundreds, if they exist...

To understand the graph, the red line (Hansen A) was calculated assuming and annual increase of atmospheric CO2 of 1.5% per year. The orange line (Hansen B) was calculated assuming that the annual increase of atmospheric CO2 would be constant, and the yellow line (Hansen C) was calculated assuming CO2 output would decrease so much after 1990 that by 2000 it would cease to increase. He was optimistic in the scenario.

"well... y'know what? even brownian motion gets it right if there's enough molecules. the trick is in being able to spot the one molecule that pops out at the right place at the right time, and this is no different, really."

Until then, you've got no reason to believe that modern observations aren't within the bounds of natural variation.

You keep repeating this fallacy. You seem to believe that just because the climate varied naturally in the past, present variation cannot be distinguished from natural variation. Natural variation isn't some unexplained statistical process, and attributing climate change doesn't arise from comparing current ranges of variation to past ranges of variation. Natural variation comes from physics. There aren't very many places where atmospheric heat can come from, and we can look in those places. Natural var